Third-harmonic generation measurement of nonlinearities in SiO2-TiO2 sol-gel films

Abstract
Third‐harmonic generation has been used to measure the magnitude and phase of the nonlinear susceptibility χ(3)(3ω) of SiO2‐TiO2 sol‐gel thin films as a function of TiO2 concentration. Nonlinearities 20 times larger than those of fused silica were found, making such films useful for nonlinear optics in glass waveguides.